In a large skillet, cook bacon over medium heat until crisp. Remove with a slotted spoon to paper towels; drain, reserving 1 tablespoon drippings. Saute onion in the drippings until tender. , Stir in sauerkraut, tomatoes, brown sugar and bacon. Bring to a boil. Transfer to a greased 1-1/2-qt. baking dish. Bake, uncovered, at 350° for 30-35 minutes or until bubbly.